The inventive concepts described herein relate to a verification method of a nonvolatile memory device.
A semiconductor memory device is volatile or nonvolatile. A volatile semiconductor memory device supports fast read and write speeds, while it loses contents stored therein when powered off. A nonvolatile semiconductor memory device retains contents stored therein, although its power is cut off. The nonvolatile semiconductor memory device, thus, is used to store data to be retained regardless of whether a power is supplied to the nonvolatile semiconductor memory device.
A flash memory device is a typical nonvolatile memory device. the flash memory device is widely used as voice and image data storing mediums of information devices, such as a solid state drive (SSD), a computer, a handheld phone, a smart phone, a digital camera, a camcorder, a voice recorder, an MP3 player, a personal digital assistant (PDA), a handheld PC, a game machine, a facsimile, a scanner, and a printer. Research on high-capacity, high-input/output, and low-power techniques of the nonvolatile memory device has been made for the past several years to mount it on mobile devices, such as the SSD and the smart phone.
A plurality of program loops may be executed to store a plurality of data bits at a memory cell, and a verification operation may be performed with respect to each program state every program loop. Thus, it is essential to shorten a program verification time in order to reduce a program time.